SAN FRANCISCO — A California appellate court has upheld dismissal of a class action accusing the maker of an ultrasonic dental scaler of misleading dentists into believing that the device can be used in surgical procedures, finding that as licensed dentists, the plaintiffs knew that the device was not safe for such use.

In a Jan. 10 ruling, the California Court of Appeal, 1st District, further held that the device’s manufacturer, Dentsply International Inc., did not promise or affirm that Cavitron was save for surgical use. As such, the court upheld dismissal of plaintiff’s Unfair Competition Law and breach of ...